A sample of isomer Y\text{Y}Y (C5H8O2\text{C}_5\text{H}_8\text{O}_2C5H8O2) was mixed with an excess of oxygen and the mixture ignited. After cooling to the original temperature, the total volume of gas remaining was 365 cm3365\text{ cm}^3365 cm3.
When this gas mixture was passed through aqueous sodium hydroxide, the carbon dioxide reacted and the volume of gas decreased to 125 cm3125\text{ cm}^3125 cm3.
Both gas volumes were measured at 20 ∘C20\text{ }^\circ\text{C}20 ∘C and 102 kPa102\text{ kPa}102 kPa.
Write an equation for the complete combustion of Y\text{Y}Y in an excess of oxygen and calculate the mass, in mg, of Y\text{Y}Y used.
The gas constant R=8.31 J K−1 mol−1R = 8.31\text{ J K}^{-1}\text{ mol}^{-1}R=8.31 J K−1 mol−1.